Leak Test And Vacuum Drying; Pipe Insulation; Additional Refrigerant Charge; Field Wiring - Panasonic CU-8ME1XPK Installation Manual

Leak test and vacuum drying

The units were checked for leaks by the manufacturer.
Confirm that the valves are firmly closed before pressure test or
vacuuming.
Air tight test and vacuum drying
- Air tight test: Make sure to use nitrogen gas.
Pressurize the liquid and gas pipes to 3.2MPa (do not
pressurize more than 3.2MPa). If the pressure does not drop
within 24 hours, the system passes the test. If the pressure
drops, check where the nitrogen leaks from.
- Vacuum drying: Use a vacuum pump which can evacuate to
-100.7kPa (5Torr, -755mmHg).
1. Evacuate the system from the liquid and gas pipes by using a
vacuum pump for more than 2 hours and bring the system to -
100.7kPa. After keeping the system under that condition for
more than 1 hour, check if the vacuum gauge rises or not. If it
rises, the system may either contain moisture inside or have
leaks.
2. Following should be executed if there is a possibility of moisture
remaining inside the pipe (if piping work is carried out during the
raining season or over a long period of time rainwater may enter
the pipe during work).
After evacuating the system for 2 hours, pressurize the system
to 0.05MPa (vacuum break) with nitrogen gas and evacuate the
system again using the vacuum pump for 1 hour to -100.7kPa
(vacuum drying). If the system cannot be evacuated to -
100.7kPa within 2 hours, repeat the operation of vacuum break
and vacuum drying.
Then, after leaving the system in vacuum for 1 hour, confirm that
the vacuum gauge does not rise.

Pipe insulation

After finishing the leak test and vacuum drying, the piping must be
insulated. Take into account the following points:
- Make sure to insulate the connection piping and refrigerant
branch kits entirely.
- Make sure to insulate the gas side connection piping and
refrigerant branch kits entirely against heat, and depending on
operation conditions (e.g. when performing cooling operation
with an outside air temperature of 15°C), consider to also make
a heat insulation of the liquid side connection piping and
refrigerant branch kits to prevent dewing.
- Use heat resistant polyethylene foam which can withstand a
temperature of 70°C for liquid side piping and polyethylene foam
which can withstand a temperature of 120°C for gas side piping.

Additional refrigerant charge

Refrigerant may only be charged after performing the leak test
and the vacuum drying (see above).
When charging a system, care shall be taken that its maximum
permissible charge is never exceeded, in view of the danger
of liquid hammer.
Charging with an unsuitable substance may cause explosions
and accidents, so always ensure that the appropriate
refrigerant (R407C) is charged.
Refrigerant containers shall be opened slowly.
Always use protective gloves and protect your eyes when
charging refrigerant.
- This outdoor unit is factory charged with refrigerant and
depending on pipe sizes and pipe lengths some systems require
additional charging of refrigerant.
- Charge the refrigerant to the liquid pipe in its liquid state. Since
R407-C is a mixed refrigerant, its composition changes if
charged in a state of gas and normal system operation would
no longer be assured.
- Determine the weight of refrigerant to be charged additionally
referring to the item "Additional refrigerant to be charged" in
chapter "Example of connection". And fill in the amount in the
"Request for the indication of additional refrigerant charging
amount and installation date" attached to the unit.
- After the vacuum drying is finished, charge the additional
refrigerant in its liquid state through the liquid stop valve service
port. Taking into account following instructions:
1. Check that suction, discharge gas and liquid stop valves are
closed.
2. Stop the compressor and charge the specified weight of
refrigerant.
- If the outdoor unit is not in operation and the total amount cannot
be charged, follow the procedures for additional refrigerant
charge shown below.
- Make sure to use installation tools you exclusively use on
R407C installations to withstand the pressure and to prevent
foreign materials from mixing into the system.
Note
Procedures for charging additional refrigerant
Refer to figure 3.
1 R407C refrigerant cylinder
2 vacuum pump
3 liquid stop valve with service port
4 gas stop valve with service port
5 valve A
6 discharge stop valve with serviceport
7 HR box
8 Indoor unit
1. Fully open the suction, discharge gas stop valve. The liquid stop
valve and "valve A" shown below must be kept closed. Start the
additional refrigerant charging operation.
2. Stop the additional refrigerant charging operation when the
specified amount is charged.
3. Fully close the liquid side stop valve. For setting the additional
refrigerant charging operation, see the "Caution on operation"
label on the rear of the front panel (left) of the outdoor unit.
Caution
1. If the refrigerant cylinder is siphonal, set it upright while charging
additional refrigerant.
F
IELD WIRING
All field wiring and components must be installed by a licensed
electrician and must comply with relevant local and national
regulations.
The field wiring must be carried out in accordance with the
wiring diagrams and the instructions given below.
Be sure to use a dedicated power circuit. Never use a power
supply shared by another appliance.
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